(19)
(11) EP 0 807 959 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
28.01.1998 Bulletin 1998/05

(43) Date of publication A2:
19.11.1997 Bulletin 1997/47

(21) Application number: 97303290.7

(22) Date of filing: 14.05.1997
(51) International Patent Classification (IPC)6: H01J 61/82
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 14.05.1996 US 649887

(71) Applicant: GENERAL ELECTRIC COMPANY
Schenectady, NY 12345 (US)

(72) Inventors:
  • Allen, Gary Robert
    Chesterland, Ohio 44026 (US)
  • Giordano, Rocco Thomas
    Garfield Heights, Ohio 44125 (US)
  • Jacobs, Gary Owen
    Willoughby, Ohio 44094 (US)
  • King, Kenneth Steven
    Chesterland, Ohio 44026 (US)
  • Dever, Timothy Peter
    Fairview Park, Ohio 44126 (US)

(74) Representative: Pedder, James Cuthbert 
GE London Patent Operation, Essex House, 12/13 Essex Street
London WC2R 3AA
London WC2R 3AA (GB)

   


(54) Arc discharge light source exhibiting high brightness properties


(57) A high brightness discharge light source (30) having improved thermal balance characteristics includes a lamp envelope (32) having an arch chamber (34) formed therein and a pair of electrodes (18,20) extending into opposite ends of the arc chamber (34) so as to be displaced form one another by a distance of no greater than 4mm. A fill disposed within the arc chamber is excited to a discharge state upon the introduction of an excitation energy coupled through the pair of electrodes (18,20). The light source (30) is operated vertically so that one of the electrodes (18) is disposed at the top region and the other electrode is disposed at the bottom region of the arc chamber (34). The arc chamber (34) is formed having a diameter dimension (D) which is just larger than the spacing between the electrodes (18,20), and a height dimension (H) which is approximately twice the diameter dimension (D) . The diameter dimension (D) is substantially uniform along the length of the arc chamber (34). The uniform diameter characteristic is effective so that the thermal operating properties associated with the discharge state are substantially equally distributed from the top to the bottom regions of the arc chamber (34) thereby resulting in extending the life of this light source (30) to approximately 6000 hours.






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